Waste pea-shells were digested under batch anaerobic conditions. Digestion of pea-shell slurries (PSS) at 1-5% total solids (TS) concentration with H-2-producing organisms yielded 99-362 l biogas-H/kg organic solids reduced (biogas-H: mixture of H-2, CO2 and H2S). Hydrogen constituted 33-46% of the total biogas-H. Methanogenesis of PSS (1-5% TS) was most effective at 1% TS level. During 25 days of incubation, 507 l biogas/kg was generated (biogas: mixture of CH4, CO2 and H2S). Methane accounted for 43% of the total biogas yield. Biogas yield of 1% TS PSS without the fibrous sheath was only 16.5% of that of 1% TS PSS with the fibrous sheath. However 3% TS PSS without the fibrous sheath showed improved results, which could be employed for continuous-culture digestions.